如何從C＃中的多個列表中獲取項目的多個組合

Question

我有三個清單

 List<string> firstList = new List<string> { "A", "B" };
 List<string> secondList = new List<string> { "C", "D", "E" };
 List<string> thirdList = new List<string> { "F", "G" };

我想要以上三個列表中的所有組合，例如

ACF
ACG
ADF
ADG
...

我嘗試了SelectMany和Zip但是沒有用。

注意：如果我使用lambda表達式獲得所需的輸出，將對您有所幫助。

Answer 1

您可以通過像這樣使用Join來做到這一點

public class Program
{
    static void Main(string[] args)
    {
        List<string> firstList = new List<string> { "A", "B" };
        List<string> secondList = new List<string> { "C", "D", "E" };
        List<string> thirdList = new List<string> { "F", "G" };

        List<string> result = firstList
                              .Join(secondList, x => true, y => true, (m, n) => m + n)
                              .Join(thirdList, a => true, b => true, (a, b) => a + b)
                              .ToList();

        result.ForEach(x => Console.WriteLine(x));
        Console.ReadLine();
    }
}

輸出：

Answer 2

您需要3個循環：

List<string> combinations = new List<string>();
for(int i=0; i < firstList.Length; i++)
   for(int j=0;j < secondList.Length; j++)
      for(int k=0;k < thirdList.Length; k++)
            combinations.Add(firstList[i]+secondList[j]+thirdList[k]);